Some recent notebook type personal computers have a built-in antenna for a wireless local area network (WLAN) or Bluetooth (registered trade mark). A planar inverted F antenna (sometimes called an “F type antenna”) suitable for transmitting and receiving high frequencies is used as this antenna and embedded, for example, at the top of a rear cover or at the top of both sides of the rear cover.
Many of today's rear covers are made of a conductive material to prevent electromagnetic radiation generated within the personal computers from leaking out. In order to allow an inverted-F antenna to transmit a radio wave to the outside and receive a radio wave from the outside, an opening is provided in a rear cover in the position where the inverted-F antenna is embedded and the opening is covered with a resin cap.
The antenna requires a ground. However, the conventional structure as described above does not allow a large ground area to be provided. Consequently, such conventional antennas have a problem that they tend to be affected by the conductive material surrounding the antenna and therefore do not provide stable transmission and reception.
Accordingly, what is needed is a system and method for overcoming the above-identified problems. The present invention addresses such a need.